I have a problem in my application. When a messaged is being processed and before the response in sent if my server is shutdown, then on restart the message is processed again. I find this behaviour unique only to JBoss. In other application servers if the message is read once, it gets deleted fro queue, after some research I found that in JBoss case, only after a response is sent, it deletes the message from queue. I want to change this behaviour please help me out.

In our application we are using MDB's with EJB 2.0 can you suggest us some API's or examples by which we can create transaction. We tried to set acknowledgement mode to CLIENT_ACK but we came to know that only AUTO_ACK and DUPS_OK are the only supported modes if we use MDB.